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| mick... |
 Posted: Thu Oct 08, 2009 4:44 pm |
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Guest
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I`ve been trying to get to know ADO.net lately and I wonder if anyone can
explain why the following does not work -
myDataSet.Clear();
myDataSet.AcceptChanges();
myTableAdapter.Update(myDataSet);
If you clear the dataset and then do the update shouldnt the database be
cleared as well. When I tried this the contents of the database are still
there when I rerun my app.
What I ended up doing was iterating throw the dataset and deleting row by
row but I`m curious why the above doesnt work.
TIA,
mick |
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| Miha Markic... |
| Posted: Fri Oct 09, 2009 1:52 am |
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Guest
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In your case Clear removes all the information from *Dataset* thus Update
won't do anything. Update does its things based on the rows in their
RowState.
--
Miha Markic [MVP C#, INETA Country Leader for Slovenia]
RightHand .NET consulting & development www.rthand.com
Blog: blog.rthand.com
"mick" <coughcough at (no spam) privacy.com> wrote in message
news:#ttrYjGSKHA.4592 at (no spam) TK2MSFTNGP06.phx.gbl...
Quote: I`ve been trying to get to know ADO.net lately and I wonder if anyone can
explain why the following does not work -
myDataSet.Clear();
myDataSet.AcceptChanges();
myTableAdapter.Update(myDataSet);
If you clear the dataset and then do the update shouldnt the database be
cleared as well. When I tried this the contents of the database are still
there when I rerun my app.
What I ended up doing was iterating throw the dataset and deleting row by
row but I`m curious why the above doesnt work.
TIA,
mick |
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| Back to top |
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| mick... |
| Posted: Fri Oct 09, 2009 8:37 am |
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Guest
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"Miha Markic" <miha at rthand com> wrote in message
news:F39C4D09-1AA5-45F1-BE03-B1288183D639 at (no spam) microsoft.com...
Quote: In your case Clear removes all the information from *Dataset* thus Update
won't do anything. Update does its things based on the rows in their
RowState.
I`ve been reading a bit more and would just like you confirm that I
understand it correctly -
When I use Clear on the DataSet it actually clears all of the entries but if
I use Delete it just "marks" entries for deletion but does not actually
perform any deletion until the update. Is this correct?
mick |
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| Miha Markic... |
| Posted: Fri Oct 09, 2009 12:00 pm |
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Guest
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Quote: I`ve been reading a bit more and would just like you confirm that I
understand it correctly -
When I use Clear on the DataSet it actually clears all of the entries but
if I use Delete it just "marks" entries for deletion but does not actually
perform any deletion until the update. Is this correct?
Yes, it will mark existing rows with RowState = Deleted. If the row doesn't
exist in database (it has been added in memory) it will be removed.
HTH,
--
Miha Markic [MVP C#, INETA Country Leader for Slovenia]
RightHand .NET consulting & development www.rthand.com
Blog: blog.rthand.com |
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| mick... |
| Posted: Fri Oct 09, 2009 8:49 pm |
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Guest
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"Miha Markic" <miha at rthand com> wrote in message
news:F5B8AF6B-99BD-4D30-ABEE-FBEF503C015F at (no spam) microsoft.com...
Quote:
I`ve been reading a bit more and would just like you confirm that I
understand it correctly -
When I use Clear on the DataSet it actually clears all of the entries but
if I use Delete it just "marks" entries for deletion but does not
actually perform any deletion until the update. Is this correct?
Yes, it will mark existing rows with RowState = Deleted. If the row
doesn't exist in database (it has been added in memory) it will be
removed.
Thanks Miha.
mick |
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